Scientists at Linköping University have developed a prototype for a synthetic muscle energy system that does not use batteries to store energy. Instead, it can, albeit not as efficiently as a living organism, obtain electrons from a mixture of glucose and oxygen. And not only glucose, which in the future will allow the robots to be fed "pasture".
Synthetic muscle is built on the basis of pyrrole polymer, the main property of which is a sharp change in volume when receiving an electric current charge. The scientists took two thin polypyrrole plates and separated them with a membrane. If current is applied to one plate, ions from it will rush through the membrane to another, where they will be absorbed. Due to the loss of particles, the first plate will contract, the second, due to excess, will expand, which from the side looks like a tense muscle bent in an arc.
The source of current in this case can be anything. Linkoping has developed a coating for the polymer from a layer of enzymes that serve as a catalyst - it is enough to lower the structure in an aqueous solution of glucose and provide access to oxygen, and the reaction of generating an electric current starts. This is the same process that occurs in living organisms, where the enzyme glucose is burned in the presence of oxygen to release energy. It remains only to modify the architecture of the system in order to minimize the loss of this energy.
At the next stage, scientists set a goal to achieve complete control over the process and check the system's performance over many cycles. If everything goes well, experiments with other enzymes will begin, fortunately, there are plenty of them in nature. And the ideal would be a power system for robots that can use any potential source of enzymes as fuel - from mud in a puddle to industrial waste.